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2024
Rotatori, F. M., Ferrari L., Sequero C., Camilo B., Mateus O., & Moreno-Azanza M. (2024).  An unexpected early-diverging iguanodontian dinosaur (Ornithischia, Ornithopoda) from the Upper Jurassic of Portugal. Journal of Vertebrate Paleontology. e2310066.: Taylor & Francis AbstractWebsite

Iguanodontia is a diverse clade of herbivorous ornithischian dinosaurs that were speciose and abundant during the Jurassic and Cretaceous. Although the monophyly of Iguanodontia is well supported, their internal relationships have sparked heated debate due to several phylogenetic paradigm shifts. Late Jurassic basally branching iguanodontians in particular are not well understood in terms of their systematic affinities and evolutionary relevance. Their fossil record in Europe is meager compared with North America, with only a few species currently recognized. Two taxa are currently known from the Upper Jurassic of England, the basally branching styracosternan Cumnoria prestwichii and the putative dryosaurid Callovosaurus leedsi. In the Upper Jurassic of Portugal, the styracosternan Draconyx loureiroi and the dryosaurid Eousdryosaurus nanohallucis are presently the only described basally branching iguanodontians. Here we report a new species of early diverging iguanodontian from the Upper Jurassic Lourinhã Formation of western-central Portugal. The new species is clearly distinguished from all other coeval taxa by an exclusive combination of characters that include a tibia with a cnemial crest that is directed craniolaterally and a fibular condyle that is angled at 90° with respect to the proximal epiphysis, a fibula with symmetrical proximal margins, and a reduced metatarsal I. The phylogenetic relationships of the Lourinhã iguanodontian were explored using maximum parsimony and Bayesian inference. The two analyses recover the Lourinhã iguanodontian as an indeterminate dryomorphan, with more precise affinities precluded due to the current available material. Body size is estimated between 3 and 4 meters for the holotype specimen, adding to the diversity of small ornithopods already recognized in the paleoichnological record of the Lourinhã Formation. http://zoobank.org/urn:lsid:zoobank.org:pub:5F4D52D0-0F0B-4809-8561-BE58C7C97D45

2023
López-Rojas, V., Clemmensen L. B., Milàn J., Wings O., Klein N., & Mateus O. (2023).  A new phytosaur species (Archosauriformes) from the Upper Triassic of Jameson Land, central East Greenland. Journal of Vertebrate PaleontologyJournal of Vertebrate Paleontology. e2181086., 2023: Taylor & Francis Abstracta_new_phytosaur_species_archosauriformes_from_the_upper_triassic_of_jameson_land_central_east_greenland.pdfWebsite

ABSTRACTHerein we describe phytosaurs from thin fluvial overbank sandstones of the Upper Triassic Malmros Klint Formation of the Fleming Fjord Group (central East Greenland). The new sample includes more than 150 disarticulated bones and teeth from small to large specimens belonging to at least four individuals. The fossils mostly consist of teeth and postcranial elements and permit the recognition of a new species of Mystriosuchus, M. alleroq, diagnosed by an L-shaped quadratojugal whose anterior suture trends anterodorsally and a tripartite degree of heterodonty. Humeral diaphyseal histology of one specimen reveals a fairly compact cortex that surrounds a cancellous medullary region followed by a remodeling zone containing scattered secondary osteons. Primary bone tissue is parallel-fibred with a moderate to low vascular density. The cortex is cyclically interrupted by distinct growth marks indicating a seasonal environment. A change in growth rate from moderate to low is documented within the outer cortex, indicating that at least this individual was close to somatic maturity. Mystriosuchus has formerly been known as an exclusively European taxon. The new findings support the European faunal influence in East Greenland during the Late Triassic inferred from other taxa such as temnospondyls and archosaurs. The mid-late Norian age of European Mystriosuchus suggests an additional age constraint for the vertebrate-bearing portion of the Malmros Klint Formation.

Coimbra, R., Moreno-Azanza M., Ezquerro L., Nuñez-Lahuerta C., Gasca J. M., Immenhauser A., Mateus O., & Rocha F. (2023).  Evaluating and comparing geochemical sampling protocols in dinosaur eggshells: refining Cretaceous ecosystem research. Cretaceous Research. 105632. Abstractsingle_file_coimbra_et_al._2023_cretresearch.pdfWebsite

The geochemical signatures of dinosaur eggshells represent well-established proxies in paleoenvironmental and paleobiological research. The variable sampling procedures reported in the literature, however, deserve attention. In order to evaluate the impact of different sampling methodologies on carbon and oxygen isotope and elemental concentrations, grinding was contrasted with drilling to extract powder samples from eggshell fragments collected at several locations. Eggshell data were further contrasted with surface materials, encasing matrix and compared with independent proxies using petrographic and elemental techniques. Iron and manganese elemental concentrations revealed an enrichment sequence depending on the sampling strategy for the same eggshell fragment. This pattern can be mistaken for a variable state of preservation. In contrast, carbon and oxygen isotope values exhibited only subtle differences and lacked clear trends. This suggests that isotope data are less susceptible to different methodological approaches. It is shown that drilling offers a wider range of possibilities compared to grinding (e.g., faster and less destructive). Additionally, drilled powder samples can confidently be used for elemental and isotope analysis, excluding contamination, thus providing a more accurate set of proxy data from eggshell archives.

Werneburg, I., Pommery Y., Ruciński M., Kästle B., Cohen G. J., Natchev N., Mateus O., & Ferreira G. D. (2023).  Functional morphology of the skull of Henodus chelyops (Placodontia). International Congress of Vertebrate Morphology Cairns - QLD - Australia 28 July - 1 August 2023. The Anatomical Record. 232-233. Abstractwerneburg_et_al_2023_henodus_icvm_2023_abstracts_updated_8_14-1693344432.pdf

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Rotatori, F. M., Quaranta M., Bertozzo F., Hübner T., Camilo B., Mateus O., & Moreno-Azanza M. (2023).  Hadrosaur-like vascularisation in the dentary of an early diverging iguanodontian dinosaur. Historical Biology. 1-6.: Taylor & Francis AbstractWebsite

ABSTRACTVirtual palaeontology is a growing field, leading palaeontologists to better understand the microanatomy of many extinct species. The application of techniques such as CT and μCT-scanning allows the researchers to study micro-anatomical features in a non-invasive way and make inferences on the palaeobiology of animals. Dinosaurs have been extensively studied using these techniques, with particular focus on the microanatomy of the cranium, whereas relatively little is known of other cranial elements, such as the lower jaw. Here, we aim to fill this gap, describing the microanatomy of the specimen ML 768, an isolated dentary belonging to a dryosaurid iguanodontian dinosaur from the Upper Jurassic of Lourinhã Fm. The dentary ML 768 was subjected to μCT-scanning, and subsequently the data were segmented in Avizo and rendered in Blender. We identified functional and replacement teeth, recognising remnants of old replacement cycles. Furthermore, we mapped a rich neurovascular network present in the dentary and compared it with reference literature. We found that the high vascularisation is shared with other cerapodan dinosaurs with high tooth replacement rates, although homoeostasis may have also played a role in the development of this condition. Further evidence is needed to appreciate the macroevolutionary significance of these findings.

Conti, S., Masarati P., Tschopp E., Zanoni A., Mateus O., & Sala G. (2023).  How to simulate soft tissues in extinct animals. Using sauropod dinosaurs as a case study. ECCOMAS Thematic Conference on Multibody Dynamics. Abstractconti_et_al_2023_id_218_424_eccomas_mbd_2023_congresso_lisbona.pdf

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Crespo, V. D., Sequero López C., Rios M., Estraviz López D., Gamonal A., Martino R., Riccetto M., Callapez P., Legoinha P., & Mateus O. (2023).  Revisiting the classical small mammal assemblage from the Eocene site of Silveirinha: a fresh look at old collections. XI Congresso Nacional de Geologia: Geociências e Desafios globaisAt: Universidade de CoimbraVolume: Livro de Resumos, págs 85-86. , Coimbra Abstractcrespov_etal_xicng2023_silveirinha.pdf

O sítio de Silveirinha é uma das localidades de mamíferos mais conhecidas da Paleontologia do Cenozoico de Portugal e da Europa em geral. Graças à sua rica e diversificada associação de mamíferos, com mais de 30 taxa, foi posicionado no Eocénico inferior (início do Ypresiano, MP7, ca. 55,8 M.a.), sendo o local mais antigo da Europa desta Época, devido à presença única de taxa típicos do Paleocénico superior, juntamente com outras espécies já características do Eocénico inferior. Este estudo irá rever o material de pequenos mamíferos deste sítio, conservado na coleção clássica da Universidade Nova de Lisboa, a fim de fazer uma actualização taxonómica à luz das publicações mais recentes.

Conti, S., Sala G., & Mateus O. (2023).  Smart Biomechanical Adaptation Revealed by the Structure of Ostrich Limb Bones. Biomimetics. 8(1), , Number 1 Abstractbiomimetics-08-00098.pdfWebsite

Ostriches are known to be the fastest bipedal animal alive; to accomplish such an achievement, their anatomy evolved to sustain the stresses imposed by running at such velocities. Ostriches represent an excellent case study due to the fact that their locomotor kinematics have been extensively studied for their running capabilities. The shape and structure of ostrich bones are also known to be optimized to sustain the stresses imposed by the body mass and accelerations to which the bones are subjected during movements. This study focuses on the limb bones, investigating the structure of the bones as well as the material properties, and how both the structure and material evolved to maximise the performance while minimising the stresses applied to the bones themselves. The femoral shaft is hollowed and it presents an imbricate structure of fused bone ridges connected to the walls of the marrow cavity, while the tibial shaft is subdivided into regions having different mechanical characteristics. These adaptations indicate the optimization of both the structure and the material to bear the stresses. The regionalization of the material highlighted by the mechanical tests represents the capability of the bone to adapt to external stimuli during the life of an individual, optimizing not only the structure of the bone but the material itself.

Rotatori, F. M., Chiarenza A. A., Moreno-Azanza M., & Mateus O. (2023).  Rise of a dinasty: macroevolutionary and biogeographic patterns of iguanodontian dinosaurs across the Jurassic–Cretaceous transition. EAVP Annual Conference of the European Association of Vertebrate Palaeontologists. 226.: Palaeovertebrata, Special Volume 1-23. DOI: 10.18563/pv.eavp2023 Abstract
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2022
Conti, S., Tschopp E., Mateus O., Zanoni A., Masarati P., & Sala G. (2022).  Multibody analysis and soft tissue strength refute supersonic dinosaur tail. 12(1), 19245., 2022 Abstractconti_et_al_2022._multibody_analysis_and_soft_tissue_strength_refute_supersonic_dinosaur_tail.pdfWebsite

Sauropod dinosaurs are well known for their massive sizes and long necks and tails. Among sauropods, flagellicaudatan dinosaurs are characterized by extreme tail elongation, which has led to hypotheses regarding tail function, often compared to a whip. Here, we analyse the dynamics of motion of a 3D model of an apatosaurine flagellicaudatan tail using multibody simulation and quantify the stress-bearing capabilities of the associated soft tissues. Such an elongated and slender structure would allow achieving tip velocities in the order of 30 m/s, or 100 km/h, far slower than the speed of sound, due to the combined effect of friction of the musculature and articulations, as well as aerodynamic drag. The material properties of the skin, tendons, and ligaments also support such evidence, proving that in life, the tail would not have withstood the stresses imposed by travelling at the speed of sound, irrespective of the conjectural ‘popper’, a hypothetical soft tissue structure analogue to the terminal portion of a bullwhip able to surpass the speed of sound.

Rotatori, F. M., Camilo B., Bertozzo F., Mateus O., & Moreno-Azanza M. (2022).  A basal ankylopollexian dinosaur from the Late Jurassic of Portugal and its implications for iguanodontian diversity. Abstract book of the XIX Annual Conference of the European Association of Vertebrate Palaeontologists, Benevento/Pietraroja, Italy, 27th June-2nd July 2022. 170-171.: PalaeoVertebrata, Special Volume 1- 2022, 224. Doi: 10.18563/pv.eavp Abstractrotatorietal_2022.pdf

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Saleiro, A., Guillaume A. R. D., Rotatori F. M., Ríos-Ibañez M., López E. D., Conti S., Martino R., Puértolas-Pascual E., Mateus O., & Moreno-Azanza M. (2022).  A beta taxonomy approach to Late Jurassic and Early Cretaceous dinosaur assemblages. Abstract book of the XIX Annual Conference of the European Association of Vertebrate Palaeontologists, Benevento/Pietraroja, Italy, 27th June-2 nd July 2022.. 176-177.: PalaeoVertebrata, Special Volume 1- 2022, 224. Doi: 10.18563/pv.eavp2022 Abstractsaleiroetal_2022-eavp.pdf

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Moreno-Azanza, M., Pérez-Pueyo M., Puértolas-Pascual E., Núñez-Lahuerta C., Mateus O., Bauluz B., Bádenas B., & Canudo J. I. (2022).  Cáscaras de huevo de los últimos cocodrilomorfos del Cretácico (Huesca, España). XXXVII Jornadas de Paleontología SEP - V Congreso Ibérico de Paleontología. p. 119. Abstract2022_moreno-azanza_etal_sep.pdf

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Jésus, V. J. P., Mateus O., Milàn J., & Clemmensen L. B. (2022).  First occurrence of a frog-like batrachian (Amphibia) in the Late Triassic Fleming Fjord Group, central East Greenland. Bulletin of the Geological Society of Denmark. 70, 117–130. Abstractbull70-117-130.pdfWebsite

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Hendrickx, C., Bell P. R., Pittman M., Milner A. R. C., Cuesta E., O'Connor J., Loewen M., Currie P. J., Mateus O., Kaye T. G., & Delcourt R. (2022).  Morphology and distribution of scales, dermal ossifications, and other non-feather integumentary structures in non-avialan theropod dinosaurs. Biological Reviews. , Number n/a Abstracthendrickxetal.2021.morphologyanddistributionofscales.pdfWebsite

ABSTRACT Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals.

Moreno-Azanza, M., Pérez-Pueyo M., Puértolas-Pascual E., Núñez-Lahuerta C., Mateus O., Bauluz B., Bádenas B., & Canudo J. I. (2022).  A new crocodylomorph related ootaxon from the late Maastrichtian of the Southern Pyrenees (Huesca, Spain). Historical Biology. 1-10.: Taylor & Francis Abstracta_new_crocodylomorph_related_ootaxon_from_the_late_maastrichtian_of_the_southern_pyrenees_huesca_spain.pdfWebsite

ABSTRACTCrocodylomorph eggs and eggshells are known as old as the Late Jurassic and are frequent components of most multiootaxic eggshell assemblages. Classified within the oofamily Krokolithidae, thei histo- and ultrastructures are conservative throughout geological time, characterised by inverted-trapezoid-shaped shell units that grow from highly spaced basal knobs and present a diagnostic tabular ultrastructure. Here, we report 327 eggshell fragments from a new fossil site from the Maastrichtian of the Southern Pyrenees, Veracruz 1, and erect a new oogenus and oospecies, Pachykrokolithus excavatum oogen. et oosp. nov. characterised by crocodyloid morphotype and a prominent rugosocavate ornamentation. Eggshells from the slightly older locality of Blasi 2b, previously reported as aff. Krokolithidae, are also assigned to this new ootaxon. Different crocodylomorph taxa coexisted during the Late Cretaceous of the Tremp Basin, hindering the attribution of Pachykrokolithus excavatum oogen. et oosp. nov. to a single clade. Nevertheless, allodaposuchid eusuchians were dominant in this ecosystem, and are the most probable producers of Pachykrokolithus excavatum oogen. et oosp. nov. eggs.

Ferrari, L., Rotatori F. M., Camilo B., Moreno-Azanza M., & Mateus O. (2022).  New specimen of dryomorphan (Ornithischia, Iguanodontia) remains from the Upper Jurassic of Portugal. Abstract book of the XIX Annual Conference of the European Association of Vertebrate Palaeontologists, Benevento/Pietraroja, Italy, 27th June-2nd July 2022.. 61-62.: PalaeoVertebrata, Special Volume 1- 2022, 224. Doi: 10.18563/pv.eavp Abstractferrarietal_2022.pdf

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Guillaume, A. R. D., Costa F., & Mateus O. (2022).  Stegosaur tracks from the Upper Jurassic of Portugal: new occurrences and perspectives. Ciências da Terra / Earth Sciences Journal. 20(1), 37-60. Abstractguillaumeetal.pdf

The record of Late Jurassic stegosaur tracks from the Lourinhã Formation (Kimmeridgian-Tithonian) is here revised. Thirty-eight dinosaur tracks, preserved as natural infill casts, are here reported, and thirty-two of them are attributed to the ichnogenus Deltapodus. Four of those present impressions of skin, with polygonal scales and random pattern. Deltapodus is the most common ichnogenus in the track record of the Lourinhã Formation. The sizes and shape suggest one single dacentrurine trackmaker, which could be Miragaia longicollum, also common in the same horizons.

Moreno-Azanza, M., Balauz B., Ezquerro L., Coimbra R., Mateus O., & Nuñez-Lahuerta C. (2022).  Unbroken dinosaur eggs accumulated together do not guarantee autochthony of the fossil assemblage. Journal of Taphonomy. 16(1-4), 129-130. Abstractmoreno-azanza_et_al_2020_unbroken_eggs.pdf

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Lategano, F., Conti S., Costa F., Mateus O., & Lozar F. (2022).  Fighter or bluffer: comparison of bending and compression in models of the caudal spines of dacentrurine and stegosaurine stegosaurs. XIX Annual Conference of the European Association of Vertebrate Paleontologists. 113. Abstract
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2021
Conti, S., Tschopp E., Sala G., & Mateus O. (2021).  Multibody simulations of diplodocid tail motion. Annual conference of the European Association of Vertebrate Palaeontologists. , 5th-9th July : European Association of Vertebrate Palaeontologistsconti_et_al_2021_diplodocid_tail._eavp_abstract.pdf
Beccari, V., Pinheiro F. L., Nunes I., Anelli L. E., Mateus O., & Costa F. R. (2021).  Osteology of an exceptionally well-preserved tapejarid skeleton from Brazil: Revealing the anatomy of a curious pterodactyloid clade. PLOS ONE. 16(8), e0254789 - ., 2021/08/25: Public Library of Science Abstractbeccari_et_al_2021.pdfWebsite

A remarkably well-preserved, almost complete and articulated new specimen (GP/2E 9266) of Tupandactylus navigans is here described for the Early Cretaceous Crato Formation of Brazil. The new specimen comprises an almost complete skeleton, preserving both the skull and post-cranium, associated with remarkable preservation of soft tissues, which makes it the most complete tapejarid known thus far. CT-Scanning was performed to allow the assessment of bones still covered by sediment. The specimen can be assigned to Tupa. navigans due to its vertical supra-premaxillary bony process and short and rounded parietal crest. It also bears the largest dentary crest among tapejarine pterosaurs and a notarium, which is absent in other representatives of the clade. The new specimen is here regarded as an adult individual. This is the first time that postcranial remains of Tupa. navigans are described, being also an unprecedented record of an articulated tapejarid skeleton from the Araripe Basin.

Fernandes, A. E., Mateus O., Bauluz B., Coimbra R., Ezquerro L., Núñez-Lahuerta C., Suteu C., & Moreno-Azanza M. (2021).  The Paimogo Dinosaur Egg Clutch Revisited: Using One of Portugal’s Most Notable Fossils to Exhibit the Scientific Method. Geoheritage. 13(3), 66., 2021 Abstractfernandes_et_al-2021-geoheritage.pdfWebsite

Found in the Upper Jurassic outcrops of Lourinhã, Portugal, and first published in 1997, the Paimogo dinosaur egg clutch is one of Portugal’s most remarkable fossils, with over one hundred eggs preserved in association with embryonic bones, of the allosauroid theropod Lourinhanosaurus. However, many questions about it have remained unanswered, even until the present day. After its discovery, this extraordinary fossil became the keystone of a small local museum, greatly kick-starting regional tourism, while also holding the fossils in trust for future generations to study. More than 20 years later, continually sustained paleontological interest from the public has even given rise to both a highly successful dinosaur theme park in the region and an aspiring UNESCO Geopark. Recently, a multidisciplinary team of preparators, paleontologists, sedimentologists, mineralogists, and geochemists revisited an unopened jacket from the original excavation using an array of techniques to address various questions. Studies are ongoing, but the corpus of information obtained and the methodologies utilized to gather data have offered an opportunity to design an exhibit around the history of the Paimogo clutch, highlighting the scientific methods involved, and asserting the importance of preserving geological heritage for the future, when new tools will doubtlessly become available to provide yet another new look at old fossils. Here, we describe our analytical procedures and present an innovative exhibit designed to introduce to the public the latest advances on the research behind an iconic piece of Portuguese geoheritage, increasing its value both as a research item and as an educational resource.

Conti, S., Mateus O., & Sala G. (2021).  Mechanical characterization of tibial bone material of an ostrich. Rossi V., Fanti F., Barbieri G., Cavalazzi B. & Scarponi D. (Editors) 2021. Paleodays 2021. Abstract Book del XXI Convegno della Società Paleontologica Italiana, live virtual edition: 127 pp.. , 15-17 June, Bologna (Italy): University of Bolognaconti_et_al_2021_ostrich_bone.pdf
Ezquerro, L., Balauz B., Coimbra R., Nuñez-Lahuerta C., Mateus O., Román T., & Moreno-Azanza M. (2021).  Evidence of sedimentary remodel of Jurassic theropod egg clutches (Lourinhã, Portugal). 18th Conference of the EAVP-Abstract book. 72-73. Abstractezquerro_et_al_2021_sedimentary_remodel.pdf

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Moreno-Azanza, M., Mateus O., Bauluz B., Coimbra R., Ezquerro L., & Núñez-Lahuerta C. (2021).  Hatching in Portugal: a new look to old eggs. XIX Encontro de Jovens Investigadores em Paleontologia. 22. Abstractmoreno-azanza_et_al_2021_eggs_ejip.pdf

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Beccari, V., Mateus O., Wings O., Milàn J., & Clemmensen L. B. (2021).  Issi saaneq gen. et sp. nov.—A New Sauropodomorph Dinosaur from the Late Triassic (Norian) of Jameson Land, Central East Greenland. Diversity. 13, , Number 11 Abstractdiversity-13-00561-v2.pdfWebsite

The Late Triassic (Norian) outcrops of the Malmros Klint Formation, Jameson Land (Greenland) have yielded numerous specimens of non-sauropod sauropodomorphs. Relevant fossils were briefly reported in 1994 and were assigned to Plateosaurus trossingensis. However, continuous new findings of early non-sauropod sauropodomorphs around the globe facilitate comparisons and allow us to now revise this material. Here, the non-sauropod sauropodomorph Issi saaneq gen. et sp. nov. is described based on two almost complete and articulated skulls. The two skulls represent a middle-stage juvenile and a late-stage juvenile or subadult. Issi saaneq differs from all other sauropodomorphs by several unique traits: (1) a small foramen at the medial surface of the premaxilla; (2) an anteroposteriorly elongated dorsoposterior process of the squamosal; (3) a relatively high quadrate relative to rostrum height; (4) a well-developed posterodorsal process of the articular. These features cannot be explained by taphonomy, ontogeny, or intraspecific variation. Issi saaneq shows affinities to Brazilian plateosaurids and the European Plateosaurus, being recovered as the sister clade of the latter in our phylogenetic analysis. It is the northernmost record of a Late Triassic sauropodomorph, and a new dinosaur species erected for Greenland. Issi saaneq broadens our knowledge about the evolution of plateosaurid sauropodomorphs.

López-Rojas, V., Mateus O., Milàn J., Wings O., Klein N., & Clemmensen L. B. (2021).  A new phytosaur from the Late Triassic of Jameson Land, Greenland. 3rd Palaeontological Virtual Congress. 207.: ISBN 978-84-09-36657-6 Abstractlopez_rojas_2021_pvc3_greenland.pdf

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Clemmensen, L. B., Lindström S., Mateus O., Mau M., Milàn J., & Kent D. V. (2021).  A new vertebrate fossil-bearing layer in the Rhætelv Formation (Kap Stewart Group) of central East Greenland: evidence of a Hettangian marine incursion into the continental Jameson Land Basin. Lethaia. n/a, , Number n/a Abstractlet.12449.pdfWebsite

The Kap Stewart Group (Rhaetian-Sinemurian, Triassic–Early Jurassic) of the Jameson Land Basin in central East Greenland has traditionally been regarded as a strictly continental unit with delta and perennial lake sediments. New finds of plesiosaur bone remain in a thin storm deposited sandstone bed in the middle part of the Rhætelv Formation of the Kap Stewart Group, however, indicates a likely period of marine influence. At the study area at the eastern margin of the basin, the Rhætelv Formation is 300-m thick and overlies unconformably the Norian Fleming Fjord Group. The bone-bearing sandstone occurs 190 m above the base of the group and is closely associated with black laminated mudstones; palynological investigation of three samples from these mudstones indicates that they are of a younger Hettangian age. The Hettangian was a relatively short stage (201.3–199.5 Ma) and elsewhere characterized by two episodes of sea-level highstands. Assuming that the marine incursion in the Jameson land Basin evidenced by the plesiosaur fossil remains took place during the youngest of these sea-level highstands, the bone-bearing bed of the Rhætelv Formation can be dated to 200 Ma and thereby gives the first numerical age constraint of this hitherto poorly dated succession.

Milàn, J., Mateus O., Mau M., Rudra A., Sanei H., & Clemmensen L. B. (2021).  A possible phytosaurian (Archosauria, Pseudosuchia) coprolite from the Late Triassic Fleming Fjord Group of Jameson Land, central East Greenland. Bulletin of the Geological Society of Denmark. 69, 71-80. Abstractmilan_et_al_2021_coprolites_greenland_bull69-71-80.pdfWebsite

A large, well-preserved vertebrate coprolite was found in a lacustrine sediment in the Malmros Klint Formation of the Late Triassic Fleming Fjord Group in the Jameson Land Basin, central East Greenland. The size and internal and external morphology of the coprolite is consistent with that of crocodilian coprolites and one end of the coprolite exhibits evidence of post-egestion trampling. As the associated vertebrate fauna of the Fleming Fjord Group contains abundant remains of pseudosuchian phytosaurs, the coprolite is interpreted as being from a large phytosaur.

2020
Park, J. - Y., Lee Y. - N., Currie P. J., Kobayashi Y., Koppelhus E., Barsbold R., Mateus O., Lee S., & Kim S. - H. (2020).  Additional skulls of Talarurus plicatospineus (Dinosauria: Ankylosauridae) and implications for paleobiogeography and paleoecology of armored dinosaurs. Cretaceous Research. 108, 104340. Abstractpark_et_al_2020_additional_skulls_of_talarurus_plicatospineus_dinosauria_final.pdfWebsite

Three new additional skull specimens of Talarurus plicatospineus have been recovered from the Upper Cretaceous (Cenomanian–Santonian) Bayanshiree Formation, of Bayan Shiree cliffs, eastern Gobi Desert, Mongolia. The skulls feature unique characters such as an anteriorly protruded single internarial caputegulum, around 20 flat or concave nasal-area caputegulae surrounded by a wide sulcus, a vertically oriented elongate loreal caputegulum with a pitted surface, an elongate lacrimal caputegulum positioned above the posterodorsal border of the maxilla, two longitudinally arranged large frontoparietal caputegulae surrounded by smaller rhomboid caputegulae, small but elongate medial supraorbital caputegulae, a posterior supraorbital caputegulum that is four times larger than the anterior one, up to three transverse parallel grooves on the dorsal surface of the posterior supraorbital caputegulum, postocular caputegulae along the ventral to posterior rim of the orbit that extend almost to the anteroventral margin of the squamosal horn, a longitudinal furrow tapering towards the apex of the squamosal horn, a lateral nuchal caputegulum four to five times larger than other nuchal caputegulae, and a pterygovomerine keel with a ventral margin that is dorsally positioned to the alveolar ridge. The phylogenetic analysis result showed that Talarurus is sister to the clade that includes the derived Asian ankylosaurines (Saichania chulsanensis, Tarchia kielanae, and Zaraapelta nomadis). It also shows that there was dispersal of ankylosaurines from Asia into western North America before the Cenomanian. Moreover, the rostral differences between Talarurus and Tsagantegia, another ankylosaur from the same formation, suggest possible niche partitioning between these taxa.

Clemmensen, L. B., Kent D. V., Mau M., Mateus O., & Milàn J. (2020).  Triassic lithostratigraphy of the Jameson Land basin (central East Greenland), with emphasis on the new Fleming Fjord Group. Bulletin of the Geological Society of Denmark. 68, 95–132. Abstractclemmensen_et_al_2020_triassic_lithostratigraphy_of_the_jameson_land_basin.pdfWebsite

The lithostratigraphy of the Triassic deposits of the Jameson Land Basin in central East Greenland is revised. The new Scoresby Land Supergroup is now composed of the Wordie Creek, Pingo Dal, Gipsdalen and Fleming Fjord Groups. This paper only deals with the lithostratigraphy of the late Early-Late Triassic continental deposits of the latter three groups with emphasis on the vertebratebearing Fleming Fjord Group. The new Pingo Dal Group consists of three new formations, the Rødstaken, Paradigmabjerg and Klitdal Formations (all elevated from members), the new Gipsdalen Group consists of three new formations, the Kolledalen, Solfaldsdal (with the new Gråklint Member) and Kap Seaforth Formations (all elevated from members), and the new Fleming Fjord Group is subdivided into three new formations, the Edderfugledal, Malmros Klint and Ørsted Dal Formations (all elevated from members). The Edderfugledal Formation contains two cyclic bedded, lacustrine members, a lowermost Sporfjeld Member (elevated from beds), and an uppermost Pingel Dal Member (elevated from beds). The lacustrine red beds of the Malmros Klint Formation are not subdivided. The lacustrine and fluvial Ørsted Dal Formation contains three new members. In the eastern and central part of the basin, the formation is initiated by cyclic bedded, red lacustrine mudstones of the Carlsberg Fjord Member (elevated from beds), while in the northwestern part of the basin the lowermost part of the formation is composed of grey fluvial conglomerates and sandstones with subordinate red mudstones of the Bjergkronerne Member (elevated from beds). The uppermost part of the formations in most of the basin is composed of cyclic bedded, variegated lacustrine mudstones and grey to yellowish marlstones of the Tait Bjerg Member (elevated from beds). The sediments in the Fleming Fjord Group contain remains of a rich and diverse vertebrate fauna including dinosaurs, amphibians, turtles, aeotosaurs, pterosaurs, phytosaurs and mammaliaforms. Most vertebrate bones have been found in uppermost Malmros Klint Formation, and in the Carlsberg Fjord and Tait Bjerg Members. The Norian–early Rhaetian, lacustrine Fleming Fjord Group was deposited at about 41° N on the northern part of the supercontinent Pangaea. Lacustrine sedimentation was controlled by seasonal as well as longer-term (orbital) variation in precipitation. Precipitation was probably brought to the basin by southwesterly winds. The lacustrine sediments of the uppermost Fleming Fjord Group show deposition during increasingly humid conditions changing the lake environment from an ephemeral lake-steppe area to a perennial lake. This evolution of lake environment suggests a change from a winter-wet temperate climate to one with precipitation throughout the year.

2019
Azanza, M. M., Coimbra R., Puértolas-Pascual E., Russo J., Bauluz B., & Mateus O. (2019).  Crystallography of Lourinhanosaurus eggshells (Dinosauria, Theropoda, Allosauroidea). Journal of Vertebrate Paleontology, Program and Abstracts. 156-157.moreno_azanza_et_al_2019_svp_abstract.pdf
Hendrickx, C., Mateus O., Araújo R., & Choiniere J. (2019).  The distribution of dental features in non-avian theropod dinosaurs: Taxonomic potential, degree of homoplasy, and major evolutionary trends. Palaeontologia Electronica. 22(3), 1-110. Abstractthe_distribution_of_dental_features_in_non-avian_t.pdfWebsite

Isolated theropod teeth are some of the most common fossils in the dinosaur fossil record and are continually reported in the literature. Recently developed quantitative methods have improved our ability to test the affinities of isolated teeth in a repeatable framework. But in most studies, teeth are diagnosed on qualitative characters. This can be problematic because the distribution of theropod dental characters is still poorly documented, and often restricted to one lineage. To help in the identification of isolated theropod teeth, and to more rigorously evaluate their taxonomic and phylogenetic potential, we evaluated dental features in two ways. We first analyzed the distribution of 34 qualitative dental characters in a broad sample of taxa. Functional properties for each dental feature were included to assess how functional similarity generates homoplasy. We then compiled a quantitative data matrix of 145 dental characters for 97 saurischian taxa. The latter was used to assess the degree of homoplasy of qualitative dental characters, address longstanding questions on the taxonomic and biostratigraphic value of theropod teeth, and explore the major evolutionary trends in the theropod dentition.

In smaller phylogenetic datasets for Theropoda, dental characters exhibit higher levels of homoplasy than non-dental characters, yet they still provide useful grouping information and optimize as local synapomorphies of smaller clades. In broader phylogenetic datasets, the degree of homoplasy displayed by dental and non-dental characters is not significantly different. Dental features on crown ornamentations, enamel texture and tooth microstructure have significantly less homoplasy than other dental features and can be used to identify many theropod taxa to ‘family’ or ‘sub-family’ level, and some taxa to genus or species. These features should, therefore, be a priority for investigations seeking to classify isolated teeth.

Our observations improve the taxonomic utility of theropod teeth and in some cases can help make isolated teeth useful as biostratigraphic markers. This proposed list of dental features in theropods should, therefore, facilitate future studies on the systematic paleontology of isolated teeth.

Mateus, O., Callapez P. M., Polcyn M. J., Schulp A. S., Gonçalves A. O., & Jacobs L. L. (2019).  The Fossil Record of Biodiversity in Angola Through Time: A Paleontological Perspective. (Huntley, Brian J., Russo, Vladimir, Lages, Fernanda, Ferrand, Nuno, Ed.).Biodiversity of Angola: Science & Conservation: A Modern Synthesis. 53–76.: Springer International Publishing Abstractmateus2019_chapter_thefossilrecordofbiodiversityi.pdf

This chapter provides an overview of the alpha paleobiodiversity of Angola based on the available fossil record that is limited to the sedimentary rocks, ranging in age from Precambrian to the present. The geological period with the highest paleobiodiversity in the Angolan fossil record is the Cretaceous, with more than 80{%} of the total known fossil taxa, especially marine molluscs, including ammonites as a majority among them. The vertebrates represent about 15{%} of the known fauna and about one tenth of them are species firstly described based on specimens from Angola.

Belvedere, M., Castanera D., Meyer C. A., Marty D., Mateus O., Silva B. C., Santos V. F., & Cobos A. (2019).  Late Jurassic globetrotters compared: A closer look at large and giant theropod tracks of North Africa and Europe. Journal of African Earth Sciences. 158, 103547. Abstractbelvedere_et_al_2019_jurassic_globetrotters_compared.pdfWebsite

Late Jurassic theropod tracks are very common both in North Africa and Europe. Two recently described ichnotaxa Megalosauripus transjuranicus and Jurabrontes curtedulensis from the Kimmeridgian of Switzerland show the coexistence of two apex predators in the same palaeoenvironment. Similar tracks can be found in tracksites from the Iberian Peninsula and from Morocco. Here, we further explore the similarities among the Swiss ichnotaxa and the other tracks from Germany (Kimmeridgian), Spain (Tithonian-Berriasian), Portugal (Oxfordian-Tithonian) and Morocco (Kimmeridgian) through novel three-dimensional data comparisons. Specimens were grouped in two morphotypes: 1) large and gracile (30 < Foot Length<50 cm) and 2) giant and robust (FL > 50 cm). The analyses show a great morphological overlap among these two morphotypes and the Swiss ichnotaxa (Megalosauripus transjuranicus and Jurabrontes curtedulensis, respectively), even despite the differences in sedimentary environment and age. This suggests a widespread occurrence of similar ichnotaxa along the western margin of Tethys during the Late Jurassic. The new data support the hypothesis of a Gondwana-Laurasia faunal exchange during the Middle or early Late Jurassic, and the presence of migratory routes around the Tethys.

Mateus, O., Callapez P. M., Polcyn M. J., Schulp A. S., Gonçalves A. O., & Jacobs L. L. (2019).  O registo fóssil da biodiversidade em Angola ao longo do tempo: uma perspectiva paleontológica. (Huntley B.J., Russo V., Lages F., Ferrand N., Ed.).Biodiversidade de Angola: Ciência e Conservação - Uma Síntese Moderna. 89-116., Porto: Arte & Ciência Abstractmateus_et_al_2019_paleobiodiversidade_angola.pdf

Este capítulo apresenta uma visão geral da paleobiodiversidade alfa de Angola com base no registo fóssil disponível, o qual se limita às rochas sedimentares, a sua idade variando entre o Pré‑Câmbrico e o pre‑
sente. O período geológico com a maior paleobiodiversidade no registo fóssil angolano é o Cretácico, com mais de 80% do total dos táxones fósseis conhecidos, especialmente moluscos marinhos, sendo estes na sua maioria
amonites. Os vertebrados representam cerca de 15% da fauna conhecida e cerca de um décimo destes são espécies descritas pela primeira vez com base em espécimes de Angola.

Park, J., Lee Y., Currie P. J., Kobayashi Y., Koppelhus E. B., Barsbold R., Lee S., Kim S., & Mateus O. (2019).  Three new skulls of the Late Cretaceous armored dinosaur Talarurus plicatospineus Maleev, 1952. Journal of Vertebrate Paleontology, Program and Abstracts. 165-166.park_et_al_2019_svp_abstract.pdf
Schulp, A. S., Mateus O., Polcyn M., c}alves G. {\cA., & Jacobs L. L. (2019).  Angola and its role in the paleobiogeography of Gondwana. Journal of Vertebrate Paleontology, Program and Abstracts. 188. Abstract
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Azanza, M. M., Coimbra R., Puértolas-Pascual E., Russo J., Bauluz B., & Mateus O. (2019).  Crystallography of Lourinhanosaurus eggshells (Dinosauria, Theropoda, Allosauroidea). Journal of Vertebrate Paleontology, Program and Abstracts. 156-157. Abstract
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Hendrickx, C., Mateus O., Araújo R., & Choiniere J. (2019).  The distribution of dental features in non-avian theropod dinosaurs: Taxonomic potential, degree of homoplasy, and major evolutionary trends. Palaeontologia Electronica. 22, , Number 3 Abstract
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Mateus, O., Callapez P. M., Polcyn M. J., Schulp A. S., Gonçalves A. O., & Jacobs L. L. (2019).  The Fossil Record of Biodiversity in Angola Through Time: A Paleontological Perspective. (Huntley, Brian J., Russo, Vladimir, Lages, Fernanda, Ferrand, Nuno, Ed.).Biodiversity of Angola: Science {&} Conservation: A Modern Synthesis. 53–76., Cham: Springer International Publishing Abstract

This chapter provides an overview of the alpha paleobiodiversity of Angola based on the available fossil record that is limited to the sedimentary rocks, ranging in age from Precambrian to the present. The geological period with the highest paleobiodiversity in the Angolan fossil record is the Cretaceous, with more than 80{%} of the total known fossil taxa, especially marine molluscs, including ammonites as a majority among them. The vertebrates represent about 15{%} of the known fauna and about one tenth of them are species firstly described based on specimens from Angola.

Park, J., Lee Y., Currie P. J., Kobayashi Y., Koppelhus E. B., Barsbold R., Lee S., Kim S., & Mateus O. (2019).  Three new skulls of the Late Cretaceous armored dinosaur Talarurus plicatospineus Maleev, 1952. Journal of Vertebrate Paleontology, Program and Abstracts. 165-166. Abstract
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2018
Mateus, O., Puértolas-Pascual E., & Callapez P. M. (2018).  A new eusuchian crocodylomorph from the Cenomanian (Late Cretaceous) of Portugal reveals novel implications on the origin of Crocodylia. Zoological Journal of the Linnean Society. , dec: Oxford University Press ({OUP}) AbstractWebsite
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Agnolin, F. L., Mateus O., Milàn J., Marzola M., Wings O., Adolfssen J. S., & Clemmensen L. B. (2018).  Ceratodus tunuensis, sp. nov., a new lungfish (Sarcopterygii, Dipnoi) from the Upper Triassic of central East Greenland. Journal of Vertebrate Paleontology. e1439834., apr: Informa {UK} Limited AbstractWebsite
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Agnolin, F. L., Mateus O., Milàn J., Marzola M., Wings O., Adolfssen J. S., & Clemmensen L. B. (2018).  Ceratodus tunuensis, sp. nov., a new lungfish (Sarcopterygii, Dipnoi) from the Upper Triassic of central East Greenland. Journal of Vertebrate PaleontologyJournal of Vertebrate Paleontology. e1439834., 2018: Taylor & Francis Abstractagnolin_et_al_2018_ceratodus_tunuensis_greenland.pdfWebsite

ABSTRACTThe fossil record of post-Paleozoic lungfishes in Greenland is currently restricted to a few brief reports of isolated and undetermined tooth plates coming from the uppermost Fleming Fjord Formation (late Norian) in Jameson Land, central East Greenland. Here, we describe Ceratodus tunuensis, sp. nov., a new dipnoan from a thin bed of calcareous lake mudstone from the ?rsted Dal Member of the Fleming Fjord Formation. The Ceratodus fossil record indicates that during the Late Triassic, this genus was restricted to the middle latitudes of the Northern Hemisphere. This record matches previous paleobiogeographical analyses and indicates that terrestrial biota during the Late Triassic was strongly influenced by paleolatitude.Citation for this article: Agnolin, F. L., O. Mateus, J. Milàn, M. Marzola, O. Wings, J. Schulz Adolfssen, and L. B. Clemmensen. 2018. Ceratodus tunuensis, sp. nov., a new lungfish (Sarcopterygii, Dipnoi) from the Upper Triassic of central East Greenland. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1439834.

Costa, F., & Mateus O. (2018).  Alcovasaurus longispinus as a dacentrurine stegosaur (Dinosauria) and contributions to the diagnosis of Dacentrurinae. XVI Annual Meeting of the European Association of Vertebrate Palaeontologists. 50.: Abstract book of the XVI Annual Meeting of the European Association of Vertebrate Palaeontologists, Caparica, Portugal June 26th-July 1st, 2018. Abstractcosta__mateus_2018_eavp_abstract.pdf

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Campos, H., & Mateus O. (2018).  The first record of placodonts in Portugal and its chronological and paleoecological implications. XVI Annual Meeting of the European Association of Vertebrate Palaeontologists. 38.: Abstract book of the XVI Annual Meeting of the European Association of Vertebrate Palaeontologists, Caparica, Portugal June 26th-July 1st, 2018. Abstractcampos__mateus_2018_eavp_abstract.pdf

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